<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search  @click="gotoSearch"></my-search>
    <!-- <my-search :bgcolor="'pink'" @click="gotoSearch"></my-search> -->
    
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view scroll-y   class="left-scroll-view" :style="{height: wh + 'px'}">
        <block v-for="(item , i) in cateList" :key='i'>
          <view :class="['left-scroll-view-item', i===active ? 'active' : '']" @click="activeChange(i)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view scroll-y="true"  class="right-scroll-view" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view v-for="(item2 , i2 ) in cateLevel2" :key="i2" class="cate-lv2">
          <view class="cate-lv2-title">
            / {{item2.cat_name}}
          </view>
          <!-- 动态渲染三级分类的列表数据 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
              <image :src="item3.cat_icon"></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  
  export default {    
    // 将 badgeMix 混入到当前的页面中进行使用
      mixins: [badgeMix],
    data() {
      return {
        // 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
        wh:0,
        //分类数据列表
        cateList:[],
        // 当前选中项的索引，默认让第一项被选中
        active: 0,
        // 二级分类列表
        cateLevel2:[],
        // 滚动条距离顶部的距离
        scrollTop:0 
      };
    },
    onLoad() {
      // 获取当前系统的信息
      const sysInfo = uni.getSystemInfoSync()
      // 为 wh 窗口可用高度动态赋值
      this.wh = sysInfo.windowHeight
      this.getCateList()
    },
    methods:{
     async getCateList(){
       const {data:res}  = await uni.$http.get('/api/public/v1/categories')
       if(res.meta.status !== 200) return uni.$showMsg()
       this.cateList = res.message
       // 为二级分类赋值
       this.cateLevel2 = res.message[0].children
      },
      activeChange(i){
        this.active = i
        // 为二级分类赋值
        this.cateLevel2 = this.cateList[i].children
        
        // 让 scrollTop 的值在 0 与 1 之间切换
        this.scrollTop =  this.scrollTop ? 0 :1 
      },
      
      gotoGoodsList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
      
      // 跳转到分包中的搜索页面
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    },
    

  }
</script>

<style lang="scss">
.scroll-view-container{
  display: flex;
  .left-scroll-view{
    width: 120px;
    .left-scroll-view-item{
      line-height: 60px;
      background-color: #F7F7F7;
      text-align: center;
      font-size: 12px;
      
      &.active{
        background-color: #FFFFFF;
        position: relative;
        
        &::before{
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}

.cate-lv2-title{
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list{
  display: flex;
  flex-wrap: wrap;
  
  .cate-lv3-item{
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    
    image{
      width: 60px;
      height: 60px;
    }
    
    text{
      font-size: 12px;
    }
  }
}
</style>
